Scoring on brake discs/rotors.

Maybe it was a temporary binding fault that has now rectified itself. Are all 4 discs as bad as that one in the picture ?
If the fronts are not so bad, it may have been a parking brake fault. Just a thought.

 

Maybe check this thread:

Brakes already!?!? | PriusChat

 

Absolutely, positively wrong. Being a hybrid has nothing to do with whether or not the rotors wear evenly.

A closer inspection would be necessary but from the picture, it doesn't really appear that the ridges are all that abnormal.
Some ripples are to be expected.

I certainly would NOT take their word that any brake repair is necessary.

 

Could all four brakes have been adjusted for some reason to cause dragging while it was used for demo, then they forgot about it until it was prepped for sale?

 

Disk brakes can't really be adjusted, say like a drum brake. OP says his wheel don't feel hot after a drive too. He also mentions driving over a hill with dusty/gritty conditions, about once a week. Maybe this is a factor??

Not sure if it's just the light or angle the picture was taken, but those rotors do look kinda abused. Very shiny and pronounced grooves.

 

The long & the short of it is - the pads gotta go, & the rotors will need to be turned/machined presuming the gouges aren't any deeper than whatever Toyota allows .... between 030" &. 050" at one time. If the surface can't be machined, you'll need replacement rotors - which you can likely pick up for ⅓ to ½ the cost at a salvage yard, that will be in way better shape than the existing ones. Is the Prius warranty not going to cover something like irregular/fast rotor wear?
.

 

that's a great thread, good find!

perhaps a call by the o/p to toyota is in order

 

Duplicate deleted

 

Yes. With all four brakes being heavily scored, I would be looking for a common denominator (environmental or operator).

I was just brainstorming and wondering if there was any reason (or practice) to purposefully set the brakes for demo in such a way that could cause such damage - such as for static display or something - and then was forgotten.

 

the key is that they were scored at the second service, but not at the first. unless they never checked.

 

Ah. I missed that. Thanx.

 

and its similar to what happened to prigirl in alan's link

 

...which was never really resolved. No follow-up report from the dealer. No photo's.

The mystery deepens.

 

it's unfortunate, but for her, the most important thing was that they replaced everything free. a likely admission of some defect(s)

 

Yes, that tends to support Sam Spade 2's "BS detector": The quickest way to make an embarrassing problem go away is the give the customer everything he/she wants... ...no questions asked.

 

I'd be inclined to do a full brake inspection, suspect so far it's just visual inspection, without disassemble? For sure measure the thickness and runout of the rotors against spec (in attached), and do the fingernail test: can you snag on those grooves, how deep are they?

Make sure the calipers are freely shifting laterally (the caliper pin lube is holding up). Take a close look at all the pads: is the wear uniform, even or bevelled. Clean and relube the pads/shims, relube the caliper pins.

Maybe the rotors are near service limits for thickness: if so replace, if not resurface? Or replace anyway, just to see how the new ones perform: maybe a bad batch of rotors??

 

And that all four are doing it and not just one. If it was a manufacturing defect in the pad/rotor, it would be just one. The likelihood of all four being defects is low, but not impossible.

Regardless, you're gonna have to get this fixed before you really need to use the brakes, like in an emergency. Is there another dealer nearby that you can visit?

 

I'm currently experiencing this issue with the rear rotors. Scoring isn't as bad but will require resurfacing once pads are out.

 

Good point. It might be a pair, say both fronts, but yeah, the odds of two different rotor part numbers (fronts and rears) having the same defect are very long.

How many miles on it? Have the rear brakes had a maintenance before?

The rears can be prone to scoring, if the caliper piston is misaligned at reassembly. You must get the piston orientation right, and well seated thus, or you will get uneven rotor wear (especially on the inside face), bevelled pad wear, steady drag and scoring on the outside rotor face.

Take a look at my attachment up the page; here's a screen grab:


The shaded zones are ridges, and it's important that the pin on back of inside pad is between those ridges, locked into place thus.